Stoker



Nov. 16, 1937. H. P. ANDERSON STOKER Filed Aug. 21, 1954 ATTORNEY.

Patented Nov. 16, 1937 1 UNITED STATES STOKER Howard P. Anderson, Erie, Pa., assignor to The Standard Stoker Company, Inc.,a corporation of Delaware Application August 21, 1934, Serial No. 740,746

3 Claims.

This invention relates generally to stokers for mechanically firing the furnaces of steam boilers and more particularly to the type of stoker that delivers fuel to the furnace through an opening in an upright wall thereof.

Stokers of the class described usually include a riser conduit mounted on the upright wall of the furnace with a floor or distributor plate portion extending into the firing opening. Ordinarily the riser conduit is in the form of a large tubular cast iron or cast steel member, constituting one of the largest and heaviest individual parts of the stoker. Because of its size and weight it places a comparatively heavy. load on the furnace wall and if the stoker is of the type which is applied to a locomotive, this heavy casting places a comparatively great load on the axles and journals at the rear end of the locomotive.

With the trend toward general use of comparatively light weight equipment and particularly in the development of comparatively light weight high speed locomotives, it is becoming more and more important to reduce the weight of the so-called specialty devices such as stokers of the type described, since this weight cannot be converted into hauling capacity. One object of the present invention, therefore, resides in the provision of a light weight stoker, particularly one in which the riser conduit is formed of light weight materials such as an alloy of aluminum.

An aluminum or aluminum alloy riser conduit cannot be applied directly to the boiler head, because, when subjected to temperatures above 500 Fahrenheit the physical properties thereof are altered to such an extent as to make the conduit unfit for the work it must perform and there are times when the flange through which the riser conduit is secured to the boiler head reaches temperatures from 1200 to 1500 degrees Fahrenheit. Furthermore, because of the high thermal conductivity of aluminum, the riser conduit would become so hot as to cause serious injury to the engine crew should they come in contact with it. It is therefore another object of the invention to provide such a construction and relation of parts adjacent the boiler head and the forward end of the stoker that the heat will be dissipated close to the boiler backhead.

More specific objects of the invention reside in the provision of a filler piece between the boiler head and the riser conduit with a number of fins to dissipate the heat and the provision and arrangement'of insulating material in novel relation with the elements at the forward end of the stoker.

With the above and other objects and advantanges in view, the invention consists in the features of construction, the combination of elements and arrangement of parts hereinafter more fully described and claimed and illustrated in the accompanying drawing, in which,

Fig. 1 is a longitudinal, vertical, sectional view of a portion of a locomotive through the boiler backwall with the novel stoker applied thereto and shown in elevation with some parts broken away; and

Fig. 2 is a view in horizontal section on the lines 2-2 of Fig. 1.

In the drawing, the numeral Ill indicates a locomotive boiler firebox provided with a boiler backwall 53. Fuel is delivered to the firebox I0 through an opening l3 in the boiler backwall 53.

The stoker selected to illustrate the use of the invention is that type wherein fuel is conveyed from a tender (not shown) through a system of conveyors including a, riser or discharge conduit 540. The fuel is delivered through the discharge conduit 540 onto a distributor plate I? which extends through the firing opening into the firebox, and is projected across the plate ll into the firebox by steam blasts issuing from a distributor head [8. A hood or cover encloses the upper portion of the discharge conduit 542i and is providedwith a hinge connection 20 by means of which it may be swung back to gain a larger entrance to the firebox I0.

As stated before, it is becoming more and more important to reduce the weight of the so-called specialty devices, such as the stoker. Accordingly, the stoker discharge conduit 540, being the heaviest single casting added by the application of the stoker, is preferably made of aluminum alloy which is only about one third of the weight of the metal used in present day design. Since as brought out above, the aluminum alloy discharge conduit 54!) cannot be directly applied to the boiler backwall 53, this invention contemplates a constructionand arrangement of parts adjacent the backwall which will permit of its use, and which will now be described in detail.

Separable filler pieces 5! and 52 are disposed between the backwall 53 and the forward end of the aluminum alloy discharge conduit 546. The filler pieces 5! and 52 are provided with the flanges 54 and 55, respectively, through which they are secured to the backwall 53 by suitable means, as by studs 56. The filler pieces also are provided with flanges 51 and 58 and the discharge conduit 540 is provided with corresponding flanges 59 and 60. Suitable means, such as studs 6|,

passing through the flanges 51, 59 and 58, 60 rigidly secure the discharge conduit to the filler pieces. Insulating material 62 separates the backwall 53 from the filler pieces 5| and 52 and insulating material 6la separates the discharge conduit 54!] from the filler pieces 5| and 52, thus preventing the heat at the backwall from being conducted back to the aluminum alloy discharge conduit. The filler pieces 5] =and-52 are preferably provided with a number of fins63 which aid in dissipating the heat close to the backwall.

Since coal does not entirely fill the discharge opening of the conduit 5M3 when the stoker is in operation, it is apparent that a portion of the cover is subjected to thedirect'heat rays from the firebox and therefore becomes quite hot. Insulating material 64 between the cover 65 and discharge conduit 54!] prevents excessive heat from being conducted to the aluminum discharge conduit 58%.

It Will-be noted that the insulation fila is parted by the distributor'head l8 which-forms a metal to metal contact with the discharge conduit 5%. In this case, however, very little heat will-be conducted to the discharge conduit, because the distributor head is provided with chambers that are normally filled'with steam which as'a cooling agent and will absorb the heat.

A preferred form of discharge conduit is-made of an alloy containing about 96'perce'ntaluminum and 4 percent copper. However,-it will be understood that alloys containing varying. percentages of aluminum together with varying percentages of other metals may be employed. A discharge conduit of aluminum-may likewise be used, but an alloy of aluminum is preferable. The cover or hood of the discharge-conduit is preferably made of cast ironbr steel, though if desired it may be made of aluminum or an aluminum alloy. 7

This invention provides for a practical application of a lightdischarge conduit, reducing the weight thereof iromapproxim'ately 700 pounds, the average weight of the discharge conduits now in use, to approximately 250 pounds and providing for thedissipation of the heat from the-furnace close to the wall thereof, thereby preventing the discharge conduit, despite its high thermal conductivity, from reaching a temperature which would impair its utility.

I claim:

1. In combination, a furnace having a wall with a firing opening therein, a stoker feed conduit extending toward said firing opening, said conduit being made of a material having a high aluminum content, the discharge end of said conduit terminating short of said wall opposite said firing opening, filler pieces joining the marginal edges of said firing opening and the dis- "'charge end of said conduit, insulating material ,f -b'ejtween the adjacent surfaces of said filler pieces and said wall and insulating material between the adacent surfacesof said filler pieces and said conduit.

2. In combination, a furnace having a wall with firing opening therein, a stoker feed conduitextending toward said firing opening, said conduit being made of a material having a 'high' aluminum content-the discharge end 'of said=conduit terminating short of said wall op- -posite ;,said. firing opening, filler-pieces joining the marginal edges of said firing opening and the discharge end .of said conduit, insulating material'between"theadjacent surfaces of said filler pieces and said-wall and insulating mate- 'rialbetween the adjacent surfaces ofsaid filler pieces' and said'conduit, said filler pieces being 'provid'ed withaplurality of laterally projecting =fi11s.

-3.- In combinatiom afurnace having aiwall with afiring opening therein, a stoker feed conduitextending toward said opening,"said conduit being made-of a' material having a highaluminum content, the-dischargeend .ofsaiclconduit terminating shorttoi said-wall opposite said firing opening, filleri pieces joining themarginal edges of =said firing opening and the discharge end of said conduit, said conduit at its upper end -ad- ,jacent the-firingopening havinga movable cover, insulating materialtbetween theadjacent'surfaces of sa'id :filler pieces and saidwall, insulating material between the-adjacent surfacesof said filler pieces and said conduit and insulating material b'etWeen' the adjacent surfaces of said conduit and its cover.

HOWARD P. ANDERSON. 

